Turbocharging an engine allows the engine to provide power similar to that of a larger displacement engine. Thus, turbocharging can extend the operating region of an engine. Turbochargers function by compressing intake air in a compressor via a turbine operated by exhaust gas flow. Under certain conditions, the flow rate and pressure ratio across the turbocharger can fluctuate to levels such that air flow may stop going through the compressor and reverse direction. In some cases, this may cause turbocharger performance issues and compressor or turbine degradation. Such events that create flow instability may be referred to as surge events. As such, a compressor surge level may be defined as a limitation of the mass air flow at the inlet of the compressor. Such turbocharger performance issues may be mitigated by adjusting the flow rate through the turbocharger, such as by adjusting one or more turbocharger bypass valves in order to avoid a surge event. However, such adjustments may be based on stored model-based data that does not provide adequate avoidance of the flow rate/pressure ratio fluctuations.